Pressman, E.*; Temple, J. G.: An Examination of the Thermoregulatory Response of the Garter Snake Thamnophis radix radix to the bacterium Aeromonas hydrophila

Research has shown that certain species of ectotherms behaviorally induce a fever in response to an infection. Research has also shown that the garter snake Thamnophis sirtalis shows a hypothermic response to bacterial infection. This preliminary experiment addresses the thermoregulatory behavior of Thamnophis radix radix in response to a bacterial (Aeromonas hydrophila) infection. It also addresses whether, if given a localized infection, Thamnophis radix radix will induce a fever only in the infected part of its body by comparing the thermoregulatory responses of snakes given localized infections to those given a general infection. Snakes were allowed to thermoregulate in an aquarium with a thermal gradient. For the general infection procedure, saline was injected intraperitoneally and 48 hours later, alcohol-killed Aeromonas hydrophila were injected intraperitoneally. For the localized infection, the same injection schedule was followed, only injections were subcutaneous. Following all injections, cloacal temperatures were measured continuously. The position of each snake on the gradient was recorded to determine patterns of thermoregulation. No temperature change was significant, thus showing neither a hypothermic nor a hyperthermic response to infection. Thermoregulatory patterns did not vary between the responses to saline and bacteria injections or between responses to subcutaneous and intraperitoneal injections.